The Animal Models and Behavioral Testing Core will provide the expertise, personnel and resources necessary to perform a variety of in vivo tests in rats and mice to enhance and extend research on drugs of abuse, addiction and HIV. The personnel in this Core have combined experience in a wide range of behavioral procedures. These include rodent models of drug reward, drug seeking, self-administration and relapse, tests of anxiety-like and depression-like behaviors, models of stress, measurements of several aspects of rodent activity, assessment of anhedonia, and tests for learning, memory and cognitive function. A former goal of the Animal Core, and now of the Animal Models and Behavioral Testing Core, is to support the breeding of mouse lines important to the research of members of the Center and the community at large. Examples of mice bred in our facility include opioid receptor, cannabinoid receptor, and chemokine receptor and ligand knockout mice. Breeding the mice in a central facility enhances the cost-effectiveness of using these mouse models and encourages sharing of data on multiple endpoints from a single mouse line. The Core Director, Dr. Unterwald, and Co-Investigators, Drs. Lynn Kirby and Sara Ward, have extensive experience with all of the endpoints and techniques supported by the Animal Models and Behavioral Testing Core (see biosketches). They will work together with investigators who wish to assess these measures in relationship to drugs of abuse, potential therapeutics, HIV, pain, and other manipulations. The overall aim of the Animal Models and Behavioral Testing Core is to provide state-of-the-art analysis of behaviors in a variety of animal models. Because of their expertise, the key personnel of the Core will work with investigators to design studies and develop new rodent models as research questions arise. They will assist investigators with the development of animal models and provide analysis of behavioral phenotypes.